1. Field of the Invention
The present invention relates to a vehicle headlamp that is capable of causing light from a semiconductor-type light source to be incident to a lens, and from the lens, illuminating the incident light as a light distribution pattern for low beam or a light distribution pattern for a high beam forward of a vehicle.
2. Description of the Related Art
vehicle headlamps of such a type are conventionally known (for example, Japanese Unexamined Patent Application Publication No. 2010-212089 and Japanese Unexamined Patent Application Publication No. 2011-113732). Hereinafter, these two conventional vehicle headlamps will be described.
A conventional vehicle headlamp of Japanese Unexamined Patent Application Publication No. 2010-212089 is provided with: a semiconductor light emitting element; a projection lens; a light guide member; a movable light shading member; and an actuator configured to move the movable light shading member. According to the conventional vehicle headlamp of Japanese Unexamined Patent Application Publication No. 2010-212089, when the movable light shading member is positioned in a non-shading location, light from the semiconductor light emitting element is caused to be incident to a respective one of the projection lens and the light guide member and then the incident light is illuminated forward of a vehicle as a light distribution pattern for side zone from the projection lens, and is illuminated forward of a vehicle as a light distribution pattern for center zone from the light guide member. Alternatively, when the movable light shading member is positioned in a shading position, light that is caused to be incident from the semiconductor light emitting element to the light guide member is shaded by means of the movable light shading member; and therefore, only a light distribution pattern for side zone from the projection lens is illuminated forward of the vehicle. In this manner, a light distribution pattern for high beam and a light distribution pattern for split high beam (a light distribution pattern for two-split high beam) can be obtained.
A conventional headlamp of Japanese Unexamined Patent Application Publication No. 2011-113732 is provided with: a light source; a lens; a first reflection surface; and a second reflection surface. According to the conventional headlamp of vehicle headlamp of Japanese Unexamined Patent Application Publication No. 2011-113732, when the first reflection surface is positioned in an open location, light from a light source is transmitted through a lens and then the thus transmitted light is illuminated forward of a vehicle as a light distribution pattern for passing. When the first reflection surface is positioned in a shading position, the light from the light source is reflected on the first reflection surface. The reflected light is reflected on the second reflection surface, and is illuminated forward of the vehicle as a light distribution pattern for cruising beam.
However, the conventional vehicle headlamp of vehicle headlamp of Japanese Unexamined Patent Application Publication No. 2010-212089 is structured in such a manner as to obtain a light distribution pattern for high beam and a light distribution pattern for split high beam, thus making it impossible to obtain a light distribution pattern for low beam and a light distribution pattern for high beam. According to the conventional vehicle headlamp of Japanese Unexamined Patent Application Publication No. 2011-113732, means for forming a light distribution pattern for cruising beam are the first reflection surface and the second reflection surface; and therefore, such a headlamp cannot be applied to a lamp unit of such type of making light from a semiconductor-type light source incident to a lens and then from the lens, illuminating the incident light as a respective one of a light distribution pattern for low beam and a light distribution pattern for high beam forward of a vehicle (a lamp unit of a lens direct emission and light distribution type).